21313124031 has 4 divisors (see below), whose sum is σ = 28417498712. Its totient is φ = 14208749352.

The previous prime is 21313124017. The next prime is 21313124039. The reversal of 21313124031 is 13042131312.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21313124031 - 2¹³ = 21313115839 is a prime.

It is a super-2 number, since 2×21313124031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21313123989 and 21313124007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313124039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3552187336 + ... + 3552187341.

It is an arithmetic number, because the mean of its divisors is an integer number (7104374678).

Almost surely, 2^21313124031 is an apocalyptic number.

21313124031 is a deficient number, since it is larger than the sum of its proper divisors (7104374681).

21313124031 is an equidigital number, since it uses as much as digits as its factorization.

21313124031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7104374680.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21313124031 its reverse (13042131312), we get a palindrome (34355255343).

The spelling of 21313124031 in words is "twenty-one billion, three hundred thirteen million, one hundred twenty-four thousand, thirty-one".